Informatics Publishing Limited

I. A. Farooqi ¹, R. N. Desai ¹

Affiliations
1 Oil & Natural Gas Commission, Dehra Dun, IN

Abstract

The Plio-Pleistocene deposits of Kashmir Valley are grouped under 'Karewas' and have been divided into two formational units separated by an angular unconformity. The upper formation is subdivided into four members which are separated from One another by three disconformity planes. Contrary to the earlier views that the entire sequence is lacustrine or partly lacustrine in origin, the authors believe that only the lower formation is lacustrine, while the upper one is recognised as glaciofluvial to fluvial in nature.

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R. Vaishali Vaghela ¹, R. N. Desai ², P. K. Patel ³

Affiliations
1 Department of Chemical Engineering, L. D College of Engg, Ahmedabad, Gujarat, IN
2 Department Of Chemical Engineering, L.D.College of Engg. Ahmedabad, Gujarat, IN
3 Rose Labs Bioscience Polymers, Ahmedabad, IN

Abstract

Nylon 6, 6 is regarded as tough and ductile materials since it exhibit high tensile elongation to break and high drop weight impact strengths. However, under conditions of stress concentration such as in the presence of sharp notches or cracks, polyamides exhibit brittle failure. This property, evaluated as notched Izod or Charpy impact tests, indicates that unmodified polyamides exhibit relatively low energies for crack propagation. Crystalline thermoplastic polymeric materials such as low carbon monomer nylons are very sensitive to craze and crack propagation and so their toughness and impact resistance properties are relatively low. Nylon 6 and 6,6 are relatively low cost engineering thermoplastics that have been found so many applications including automotive industry. However, relatively low impact and bending resistance of these materials especially at low temperatures and high deformation rates, restrict applications of these materials. Rubber toughening can be considered as an economical and effective method to toughen and extend applications of nylon without any important increase in its price or decrease in its engineering properties. Many rubbers such as EPR, EPDM (ethylene propylene- diene monomers), NR (nitrile rubber), SBR (styrene-butadiene rubber), and SEBS (styrene ethylene- butadiene-styrene tri-block copolymer) have been successfully used in toughening of thermoplastic materials. However, most rubbers are not compatible with nylon and cannot be finely dispersed in it. To overcome this deficiency, polyamides have been blended with several types of impact modifiers that are typically elastomeric or low modulus type olefinic polymers. However, the inherent immiscibility of polyamides with other polymers such as olefinic rubbers necessitated the development of proper compatibilization techniques to reduce the interfacial tension and improve the dispersability of the rubber for effective impact modification. This development in the area of nylon 6, 6/EPDM blend may give the more advantageous characteristics of the presently available nylon and may compensate the deficiencies of the same.

Keywords

Nylon 6, 6, EPDM, Impact Strength, Polymer Blending, Polyamides.

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K. K. Dhamecha ¹, B. H. Shah ¹, R. N. Desai ², P. K. Patel ³

Affiliations
1 Department of Chemical Engineering, L.D. College of Engg, Ahmedabad, Gujarat, IN
2 Rubber Technology Department, L.D.College of Engg, Ahmedabad, Gujarat, IN
3 Roselabs Biopolymers Pvt. Ltd., Ahmedabad, Gujarat, IN

Abstract

Butyl rubber (polyisobutylene-co-isoprene (IIR)) is a very important commercial elastomer with many desirable physical properties, such as low air permeability and broad damping properties. The principal uses of this material are in the tire industry for the preparation of inner tubes and inner liners of passenger car tires. Despite these unique properties, there are some deficiencies associated with this polymer, mainly poor compatibility with other materials, including elastomer, plastics and carbon black. This poor compatibility greatly limits the application of butyl rubber in many application areas. In fact, the improvement of interfacial adhesion among butyl rubber has been an intense research area for some time. On other hand, polyolefin elastomers (POEs) are available with properties ranging from amorphous to crystalline, and low to very high molecular weight, providing superior elasticity, toughness and low temperature ductility and offer a unique combination of flexibility and toughness, making them a material of choice for a wide variety of applications. They are versatile polymers that offer excellent adhesion at high and low temperatures, outstanding processability, and superior levels of performance in packaging and other applications. Further advantages include optimize processing and end-use performance, excellent thermal stability and UV resistance. POE’s cover a range of melt index and comonomer content (density) for use in several applications. The cost effectiveness of POE is limited by the combination of reduced flowability and/or softness requirements. The ability to extend POE with conventional process oils allows greater flexibility to compounder to tailor the performance of the product. Here retention of physical properties can be achieved by increased molecular weight of POE with addition of oil without compromising with processibility. Here the research is being made on the binary blend containing IIR and POE (IIR/POE blend). The work is to be done for testing an array of compounded butyl rubber with 10%, 15%, and 20% POE. It is to be expected that the IIR/POE blend will have dramatically better properties as POE levels rise. This development in the area of butyl rubber/POE blend may give the more advantageous characteristics of the presently available butyl compound without compromising the processibility characteristics of parent compound at moderate cost. Thus the modified form of butyl can have a set of more desirable properties and therefore it may be used more advantageously.

Keywords

Polymer Blend, Butyl Rubber, BIIR, Polyolefin Elastomer (POE).

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Vrutti Shah ¹, R. N. Desai ², P. K. Patel ³

Affiliations
1 Department Of Chemical Engineering, L.D. College of Engg. Ahmedabad, Gujarat, IN
2 Department of Chemical Engineering, L.D. College of Engg, Ahmedabad, Gujarat, IN
3 Roselabs Polymers Pvt. Ltd. Ahmedabad, Gujarat, IN

Abstract

The future of pharmaceutical industry is now shifting from new drug research to novel drug delivery systems. Biopharmaceuticals present challenges because of their unique nature and difficulty in delivery through conventional routes. These challenges inspire for the invention of new medical grade polymers for novel drug delivery systems. Polymeric drug delivery systems bring a true benefit over glass. Polymer provide improved robustness against breakability and better ergonomy, while delivering for many product an adequate stability performance level regarding water/gas permeability as well as extractible/leachable. Polycarbonate and Cyclic Olefin Copolymer are an excellent substitute of glass drug delivery systems because of its unique characteristics. Polycarbonate falls under the category of Amorphous polymers that is used as clear as glass but lighter and less prone to breakage. Polycarbonate and Cyclic Olefin Copolymer are also more resistant to water transmission than Polypropylene which was first time used for polymeric prefilled drug delivery systems. Due to this extra ordinary property it lengthen the shelf life of the drugs. Cyclic Olefin Copolymer provides an impressive array of physical and chemical properties that are attractive to drug makers, like high heat resistance: material is autoclvable, excellent low temperature characteristic, high break resistance, high transparency, low extractables, solvent resistance, wide range of pH stability, easy safe and environmentally friendly disposal. Because biocompatibility is essential for any material used in direct or indirect contact with patients, Polycarbonate and Cyclic Olefin Copolymer grades comply with biocompatibility testing standards such as ISO 10993-1 and USP Class VI. Due to this extra ordinary combination of physical-chemical properties and biocompatibility with drug formulations, Polycarbonate and Cyclic Olefin Copolymer can be used for pre-filled syringes, needleless injectors and other drug delivery systems.

Keywords

Polymeric Drug Delivery Systems, Polycarbonate, Cyclic Olefin Copolymer, Glass Drug Delivery Systems, Physical and Chemical Properties, Biocompatibility With Drug Formulations.

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